1、1. MIL-T-7976 LI9 9999906 0258LI52 3 a o f -J7/ v MIL-T- 87976 16 June 1985 MILITARY SPECIFICATION TEST STAND, HYDRAULIC SYSTEM COMPONENTS This specification is approved for use by all Departments and Agencies of the Department of Defense. SCOPE 1.1 Scope. This document covers the requirements for a
2、 non-portable test stand that will test aircraft hydraulic components, 2, APPLICABLE DOCUMENTS 2.1 Government documents. 2.1.1 Specifications and standards. Unless otherwise specified (see 6,2), the following specifications and standards of the issue listed in that issue of the Department of Defense
3、 Index of Specificaeions and Standards (DoDISS) specified in the solicitation, form a part of this specification to the extent specified herein. SPECIFICATIONS MILITARY MIL-P-116 MIL-H-5440 MIL-R-5520 MIL-H-5606 MIL-H- 6 08 3 MIL-S-26716 MIL-F-27 656 Preservation, Methods of Hydraulic Systemss Aircr
4、aft, Type I and II, Design and Installation Requirements for. Reservoir, Aircraft, Hydraulic, Nonseparated Type. Hydraulic-Fluid, Petroleum Base, Aircraft, Missile and Ordnance. Hydraulic Fluid, Petroleum Base, for Preservation and Testing. Stand, Test, Aircraft Hydraulic Systems, Non- Portable, Gen
5、eral Specification. Filter Unit , Fluid, Pressure MXU-408/M, 5 Micron, Hydraulic. . Beneficial comments (recommendations, data which may be of use in improving this document should be addressed to: the Engineering Division, San Antonio ALC/MMEDO, Kelly AFB, Texas 78241 by using the self-addressed St
6、andardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. u_ FSC 4920 DISTRIBUTION STATEMENT A. Approvedfor public release; distributionis unlimited. THIS DOCUMENT CONTAINS 13 PAGES Provided by IHSNot for ResaleNo reproduction or networking permit
7、ted without license from IHS-,-,-MIL-T-87976 ri9 999990b 0258Y53 5 = MIL-T- 87976 STANDARDS FEDERAL FED-SMI-595 Colors MILITARY MIL-STD-129 MIL-STD-4 54 MIL-STD-470 MIL= STD-7 9 4 MIL-STD-808 MIL-STD-882 1-1s 3 3 6 11 MS2 19 19 MS 33 656 Marking for Shipment and Storage. Standard General Requirement
8、s for Electronic Equipmen t. Maintainability Program Requirements (for Systems and Equipment). Parts and Equipment Procedures for Packaging and Packing of, Finish, Protective, and Codes for Finishing Schemes for Ground and Ground Support Equipment, System Safety Program Requirements. Clamp, Loop-Typ
9、e, Cushioned, Support. Tube, Bend Radii Fitting End, Standard Dimensions for Flared Tube Connector and Gasket Seal. AIR FORCE - NAVY AERONAUTICAL AND10059 AND10104 Tubing, Steel, Corrosion Resistant, Round AND20001 Drive-Type XI Engine Accessory. AND20002 Drive-Type XII Engine Accessory. Fitting - S
10、tyle of Pipe Threaded Flared Tube and Hose. Standard Dimensions for. (Copies of specifications and standards required by manufacturers in con- nection with specific acquisition functions should be obtained from the con- tracting activity or as directed by the contracting officer.) 2.1.2 Other public
11、ations, The following document(s) form a part of this specification to the extent specified herein, which are indicated as DoD adopted shall be the issue listed in the current DoDISS and the supplement thereto, if applicable. The issues of the documents AMERICAN SOCIETY FOR TESTING AND MATERIALS (AS
12、TM) ASTI1 D 3951 Standard Practice for Commercial Packaging. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-R . -.r MIL-T-87776 47 7777706 0258454 7 , i ! O I I , ! 1 i. I f t ! I i. L MIL-T-87976 (Applications for copies of ASIIM publications sho
13、uld be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, PA 19103.) AMERICAN STANDARDS C-50 Rotating Electrical Machinery. (Copies of the ASA standard.s may be obtained from the American Standards Association, 10 East 40th Street, New York, NY 10016.) NATIO
14、NAL ELECTRICAL MANUFACTURERS ASSOCIATION Standard MG-1 Motors and Generators. (Copies of the NEMA may be obtained from the National Electrical Manufac- turers Association, Engineering Department, 155 East 44th Street, New York, NY 10017. ) NATIONAL FIRE PROTECTION ASSOCIATION Code 70 National Electr
15、ical Code (Electric Wiring Apparatus) . (Copies of the NFPA may be obtained from the National Fire Protection Asso- ciation, 60 Batterymarch Street , Boston, MA, 02110.) * 2.1.3 Order of precedence. In the event of a conflict between the text of this specification and the references cited herein, th
16、e text of this specifica- tion shall take precedence. 3. REQUIREMENTS 3.1 General. Each test stand console shall meet the requirements of MIL-S-26716. Detail requirements specified herein supplement or alter the requirements of MIL-S-26716. The requirements specified herein are minimum; items provid
17、ing additional characteristics, greater accuracy and improved per- formance will be acceptable. 3 12 General requirements. The requirements of MIL-H-5440 for materials , fluids, reservoir venting, tubing, and cleaning of parts and systems apply as requirements of this specification with the exceptio
18、ns and additions specified herein. This test stand shall be designed for the performance testing of hydraulic system components such as valves, actuating cylinders, solenoid Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-8797b Li9 W 777790b O2
19、58455 7 W MIL-P.87976 valves, reservoirs, accumulators, pumps, etc., using either MIk-H-5606 gr MIL-11-6083 hydraulic fluids at an operating temperature of 100 F to 160 F. The test stand shall contain the following basic flow and pressure circuits or capabilities : a, A pump test circuit suitable fo
20、r testing fixed and variable volume pumps with displacements up to 30 GPM, discharge pressures up to 3200 pcig, inlet pressures from O to 150 psig, and case drain flows from 0.13 to 1.66 gpm at pressures from O to 160 psig. b, A 500 to 5000 rpm variable speed drive which shall deliver sufficient tor
21、que to drive a hydraulic pump with a displacement of 30 gpm at 3750 rpm and at a pressure of 3000 psig. c. A hydraulic static pressure circuit capable o? generating hydrostatic pressures up to 25,000 psi. d, h pneumatic static pressure test circuit capable of providing pres- sures up to 3,000 psig.
22、A dynamic test circuit: capable of testing a variety of aircraft com- ponents such as actuating cylinders, relief valves, selector valves, shuttle valves, etc., at flow rates up to 30 gpm with pressures up to 3750 psig and back pressures up to 200 psig, capable of generating 5000 psig pressures at r
23、educed flow rates. P e, The system shall be f, DC and AC electrical power supplies. g, I-feasuring instruments and circuits shall be provided so that the above can be measured throughout their various ranges. 3.2.1 Cabinet. The test stand equipment shall 5e located within a two section cabinet. One
24、section shall contain the drive console and the other section shall contain the control console, In use the two sections are to be fastened together, contractor furnished. All hardware required to make this connection shall be 3.2.1.2 Drive console cabinet. The drive console cabinet shall contain th
25、e variable speed drive, pump test mounting pad, panel, hydraulic and pneu- matic ports, high pressure filter, ripple filter, sink, shield, main system hydraulic pump with electric motor, pump volume and pressure controls, and necessary electrical components. controls including the variable speed dri
26、ve controls, indicating instruments, electrical power supplies, hydraulic reservoir, hydraulic and pneumatic cir- cuit, panel, sink, writing table top, sink type storage and other necessary components as required herein. 3.2.1.2 Control console cabinet. The control console cabinet shall contain 3.2.
27、1.2.1 Writing top and storage. The control console cabinet shall in- clude 8 21 X 34 inch (minimum) writing table top coated with a material 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1 MIL-T-7976 47 W 9999906 0258456 O W MIL-Te87976 resistant
28、 to damage from dropped wrenches, scratching, etc. The table top shall be hinged to provide access to the deep sink type storage area which shall also be provided. (minimum) and shall be provided with a drain connection. The storage area shall be 17 X 30 X 8 inch deep O 3.3 Hydraulic and pneumatic s
29、ystems. The test stand shall include hydraulic and pneumatic systems to comply with requirements specified herein. 3.3.1 Hydraulic and pneumatic circuits. The test stands hydraulic and pneumatic system circuits shall conform to the schematic shown on figure 1. The test stands actual hydraulic and pn
30、eumatic system schematic shall be included on a suitably engraved metal sheet and installed on the main panel at a position where it can be read easily. 3.3.2 Plumbing. The test stands fluid lines and fittings shall be of sufficient size and strength, and shall be fabricated from materials suffi- ci
31、ent to meet requirements specified herein. l 3.3.2.1 Tubing. circuits may be aluminum alloy tubing. the hydraulic circuits shall be annealed, stainless steel seamless tubing. The minimum radii of tubing bends shall be in accordance with MS33611. All low pressure or suction tubing used in hydraulic o
32、il All high pressure tubing used in 3.3.2.1.1 Tubing supports. Tubing or pipe shall not be welded to supports. All supports shall be of the clamp type conforming to the requirements of MS2199. 3.3 Tubing Tubing .2.1.2 Tubing dimensions. Tubing dimensions shall conform to AND10104. in the 5000 psi ci
33、rcuits shall be designed to 20,000 psi burst pressure. in the 25,000 psi circuit shall be designed to 75,000 psi burstpressure. Return lines shall be designed to burst pressure equal to 400 percent of the maximum operating pressure. The cross sectional area of the tubing shall be such that cavitatio
34、n, turbulence, or undue-temperatures rise will not be developed in the system. velocity shall not exceed 18 feet per second in operating valves and lines. Velocities- in return and suction lines shall not exceed five feet per second. The maximum-fluid velocity through any instrument shall be as requ
35、ired for proper operation. 125 psi maximum working pressure. size. Tube sizes shall be such that the maximum fluid The suction and return lines shall be designed for Valve size to be compatible with tube 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-
36、,-,-MIL-T-87976 Y9 497990b 0258457 2 MIL-T-87976 3,3.2.1.3 Fittings. All high pressure line fittings and panel mounted bulldiead fittings shall be of the flared tube type conforming to standard AND 10059. Pittings used in the water, low pressure hydraulic and low pressure air lines may have ends of
37、the National Pipe Thread (NPT) type. mter and air line (inlet) bosses shall be of the NPT type. is acceptable for sealing threaded joints. High pressure fittings shall be corrosion resistant steel. The external Teflon tape 3.3.2.2 Flexible hose. Flexible hose and the use thereof shall conform to the
38、 applicable requirements of MIL-S-26716. finish as corrosion preventitive measure on hose fittings and hose ends ie; acceptable I In addition, black oxide 3.3.3 however, the control shall operate successfully with cooling water of a lower temperature than specified, The temperature control shall mai
39、ntain the temperature within the required limits during all conditions normally encountered during the test. response of the control shall be fast enough to maintain the temperature within the required limits during transient conditions to permit uninterrupted testing. The control shall also indicat
40、e actual oil temperature and No manual control valves shall be required in addition to the Shutoff valves shall be interlocked to operate automatic- The temperature of the The 10 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T- 87976 All valve
41、parts coming in contact with the cooling water shall be of bronze or other corrosion-resistant material. The valve locations shall afford easy access for adjustment or repairs. A flow dividing valve may be used in the return line to control temperature, but it shall be designed so that it cannot blo
42、ck the return line under any condition. 0 3.3.3.4.3 Cooling water filter. A removable screen water filter shall be placed in the cooling water supply line immediately preceding the oil tempera- ture control valve. greater than that of the heat exchanger cooling coil. All filter parts shall be made o
43、f brass, bronze, or an equally corrosion-resistant material. The filter screen shall have not less than 60 nor more than 80 mesh per inch and shall have reinforced edges. The filter shall have a minimum capacity of 25 percent 3.3.3.4.4 Maizual water control valve. A slow closing globe or gate type v
44、alve shall be installed in ehe cooling water supply line. .The valve hand wheel shall be easily accessible and when in the closed position shall shut off the water supply to the filter, thermal control valve, and the cooling coil. 3.3.3.5 Sump drain. The drain must not have.a return system to avoid
45、any contamination or pollution possibilities. 3.3.3.6 Heaters. Heating of the test fluid to raise its temperature shall be by the use of low watt density immersion heaters (instead of by steam as required by MIL-S-26716). Electrical immersion heaters used for heating test fluid must be UL approved f
46、or this purpose and shall be designed so the heating elements are submerged a minimum of six inches below the surface of the fluid at all times. The fluid well in which the heating elements are installed shall be equipped with a low fluid level switch that shuts the test stand off automatically when
47、 the fluid level is less than six inches above the heating elements. The fluid well shall also be equipped with a UL approved over- temperature switch that shuts the heater off automatically when the test fluid temperature reaches 180 F. O 3.3.3.7 Relief valves. Commercial type relief valves may be
48、used and shall be selected for ease of adjustment and maintenance, long life, and suitability for the purpose. The main relief valves shall be adjustable between 500 and 5000 psi. 3.3.37.1 Bypass valve. A panel mounted throttling valve (bypass) installed parallel to the high pressure (main) system r
49、elief valve, or an equivalent alternate provision, shall be provided to allow test fluid warmup without upsetting the high pressure system relief valve setting. 3.3.3.8 Hydraulic pump. The stand shall be equipped with a hydraulic pump with a capacity of 30 gPm at 3750 psi and reduced flow at 5000 psi. shall be of the variable volume, axial piston type, with pressure balanced piston shoes. regulation of maximum volume delivered by the pump. The pump shall
